It has been known that polarization information is used for image processing (Japanese Laid-open Patent Publication No. 2011-29903, Japanese Patent No. 4563513, Japanese Laid-open Patent Publication No. 2012-185602, Japanese Laid-open Patent Publication No. 2002-286862 and the like).
For example, it has been known that in an image capturing device such as a camera, “a polarization filter divided into areas” is arranged on an image capturing element, and a polarization direction of light obtained by a pixel is changed to take an image.
Further, there has been known a method for outputting “a picture” by using Obtained brightness information as a brightness image and using the obtained polarization information as color information.
For example, Japanese Laid-open Patent Publication No. 2011-29903 describes a method which includes obtaining “an image including polarization information” by using the polarization filter and outputting the image by regarding a normal vector of the polarization information as the direction of an arrow.
Japanese Laid-open Patent Publication No. 2011-29903 also describes a method which includes determining a visible ray spectrum according to a polarization angle and “reconstructing each pixel by color coding” according to the polarization angle.
In the method described in Japanese Laid-open Patent Publication No. 2011-29903, the polarization information of the output image is expressed with “the arrow and the color”. Thus, when the polarization information is used, it is impossible to use “a general process on the brightness image”.
For example, even if one intends to use the image including the polarization information of a vehicle-mounted camera for “recognition of a white line on a road surface”, it is impossible to perform a process based on “an algorithm for the white line recognition using brightness”.
In other words, it is necessary to newly develop “white line recognition processing used for the polarization information expressed as color”.